ORNL Mice Helping Researchers Isolate, Identify Causes Of Cancer

OAK RIDGE, Tenn. -- Mice may have a reputation for being
quiet, but they're telling researchers at the Department of Energy's (DOE)
Oak Ridge National Laboratory (ORNL) something about the causes of leukemia,
lymphoma and other illnesses in people.

"Lymphomas that develop spontaneously in the mouse are very useful for our
studies because mouse leukemias and lymphomas are very similar to human
leukemias," said Monica Justice, a genetics researcher in ORNL's Biology
Division. "In addition, mouse lymphomas have genetic characteristics that
allow us to isolate the genes involved in the development of the cancer."

Included in ORNL's inventory of 120,000 mice are 1,000 strains, some of
which were originally bred to study the genetics of cancer.

"Some of these mouse strains have a high spontaneous incidence of lymphoma
and/or leukemia," Justice said.

When these mouse strains were first developed, scientists didn't know the
reason the mice developed leukemia. Now, however, Justice and colleagues
know that the mice get cancer because of murine leukemia retroviruses.

"One way these retroviruses can cause cancer is to integrate near and change
the normal function of cancer-causing genes," Justice said. Molecular probes
for the retroviruses provide researchers with "tags" to identify genes that
cause cancer. By studying the normal role of these genes that ultimately
cause cancer in mice, Justice hopes to understand their role in cancerous
growth when they are altered by the retrovirus.

In addition to her work with murine leukemia retroviruses, Justice has
discovered a direct correlation between Chediak Higashi Syndrome in humans
to what's simply called "beige" in mice. In people, the syndrome causes
partial albinism, an increased susceptibility to infections and a
predisposition to non-malignant lymphoma. Beige mice have the same clinical
symptoms as humans.

This similarity in diseases, along with comparative mapping studies, led
Justice and collaborators to trace the mouse gene in an effort to learn the
cause of the human disease. Justice and colleagues identified the disease
gene in mice and used the mouse gene to identify the human gene. This
information has led to the discovery of the cause of clinical symptoms in
humans.

Because of the genetic similarity between mice and humans, researchers hope
to gain a better understanding of the development of certain human cancers,
to earlier diagnoses and to better treatment strategies.

This research was funded by the National Cancer Institute and the American
Cancer Society.

ORNL, one of DOE's multiprogram research facilities, is managed by Lockheed
Martin Energy Research Corp.
You may read other press releases from Oak Ridge National Laboratory or
learn more about the lab if you have access to the Internet. You can find
our information on the World Wide Web at http://www.ornl.gov

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